package $package;

import java.util.Map;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

/**
 * <p>
 * Spring 工具类 ，获取Spring容器中的上下文信息
 * </p>
 * <p>
 *  使用的时候需要注入到applicationContext.xml 如下设置：
 *  <br>
 *  <!-- 获取ApplicationContext上下文 -->
 *	<bean id="springContextHolder" class="com.itqimeng.common.util.SpringContextHolder" />
 * </p>
 */
public class SpringContextHolder  implements ApplicationContextAware{

	private static ApplicationContext applicationContext;
	/**
	 * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量.
	 */
	public void setApplicationContext(ApplicationContext applicationContext) {
		SpringContextHolder.applicationContext = applicationContext; // NOSONAR
	}

	/**
	 * 取得存储在静态变量中的ApplicationContext.
	 */
	public static ApplicationContext getApplicationContext() {
		checkApplicationContext();
		return applicationContext;
	}

	/**
	 * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String name) {
		checkApplicationContext();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	public static <T> Map<String,T> getBean(Class<T> clazz) {
		checkApplicationContext();
		return applicationContext.getBeansOfType(clazz);
	}
	/**
	 * 清除applicationContext静态变量.
	 */
	public static void cleanApplicationContext() {
		applicationContext = null;
	}

	private static void checkApplicationContext() {
		if (applicationContext == null) {
			throw new IllegalStateException("applicaitonContext未注入,请在applicationContext.xml中定义SpringContextHolder");
		}
	}
	
}
